What specific federal law and amendment is the Supreme Court ruling interpreting?

What specific federal law and amendment is the Supreme Court ruling interpreting? What federal official is responsible for enforcing this law? In the Mississippi case, give some examples of information that the older police officers might have presented to have the Supreme Court rule in their favor?

In the age bias case Smith v. City of Jackson, the Supreme Court is interpreting the Age Discrimination in Employment Act by ruling that “disparate impact claims” are allowed by law. These claims allow workers to be protected from workplace policies that seem neutral and that were not meant to do harm to older workers, but that actually disproportionately affect older workers. The Court ruled that disparate impact claims have a precedent under Title VII of the Civil Rights Act of 1964. The Attorney General of the United States is responsible for enforcing this law. The police officers in the case lost, because the Court ruled that the higher raises given to junior members of the police department was “reasonable” because it was intended to pay a junior salary that is competitive with neighboring police forces. To win the case, the older police officers could have presented evidence that the raises given to the junior officers meant that there were no funds left to give raises to older officers that neighboring police forces regularly give to their older employees.